📌 Chapter Snapshot
6
Types of Pollution
6
Water-borne Diseases
65 dB
Noise Pollution Threshold
1981
Air Pollution Act
- This chapter covers all major types of environmental pollution — Air, Water, Soil, Noise, Radioactive, and Solid Waste — with their causes, impacts, and government control measures.
- Special focus on disease-pollutant matching (Minamata–Mercury, Itai-Itai–Cadmium, etc.) which is a very common BPSC/BSSC MCQ pattern.
⚡ QUICK RECALL
Disease-Cause matching: Minamata → Mercury | Itai-Itai → Cadmium | Black Foot → Arsenic | Blue-baby Syndrome → Nitrates.
🧪 Pollutants — Primary & Secondary
| Primary Pollutants | Secondary Pollutants |
|---|---|
| DDT, plastic, CO, CO₂, NO₂, SO₂, particulate matter, etc. | O₃, NH₃, HNO₃, H₂SO₄, SO₃, etc. (formed via reactions like Acid Rain) |
⚠ EXAM TRAP
Primary pollutants are emitted directly (CO, SO₂); secondary pollutants (O₃, Acid Rain components) FORM in the atmosphere from reactions between primary pollutants — don't classify Ozone or Acid Rain as primary.
💨 Air Pollution
| Causes | Pollutants | Impacts |
|---|---|---|
| Fossil fuels (incomplete combustion of coal, petrol), industrial waste, harmful gases from vehicles, fine particulate matter, etc. | Gaseous: CO, CO₂, SO₂, NO₂, etc. | Particulate: Aerosols, smoke, soot, smog, suspended particles, etc. | Asthma, eye irritation, respiratory diseases, brain and kidney disorders, lung cancer, etc. |
⚡ QUICK RECALL
Government efforts against air pollution: Air (Prevention and Control of Pollution) Act, 1981 & National Air Quality Monitoring Programme.
💧 Water Pollution
- Undesirable gases, liquids, and solids getting mixed into water.
| Human Induced Causes | Natural Causes |
|---|---|
| Domestic/Industrial waste, use of chemicals & pesticides in agriculture, oil spills, nuclear waste, etc. | Volcanic ash, dust, organic waste from forests, etc. |
Water-borne Diseases & Their Cause/Agent
| Disease | Cause / Agent |
|---|---|
| Jaundice | Virus |
| Minamata Disease | Mercury |
| Blue-baby Syndrome | Nitrates |
| Cholera, Typhoid, Dysentery | Bacterial |
| Itai-Itai Disease | Cadmium |
| Black Foot Disease | Arsenic |
⚡ QUICK RECALL
BOD (Biochemical Oxygen Demand) = amount of oxygen required for decomposition by microorganisms — higher BOD means more organic pollution (increase in bacteria/fungi in reservoirs).
⚠ EXAM TRAP
Government efforts: Ganga Action Plan (older) vs Namami Gange Programme (current, comprehensive) — both target Ganga river conservation, but are different schemes from different eras.
🌍 Soil Pollution
- Soil Pollution → Degradation of soil quality.
| Causes | Measures | Impacts |
|---|---|---|
| Use of chemicals, soil erosion, overuse of fertilisers, industrial/urban waste, etc. | Control on chemical fertilisers, disposal of solid waste, use of bioremediation techniques, ban on nuclear explosions, etc. | Loss of essential soil properties, decline in fertility, spread of diseases through soil |
🔊 Noise Pollution
- Noise Pollution = sound intensity above 65 decibels (dB).
| Natural Causes | Human-Induced Causes |
|---|---|
| Thunder of clouds, earthquake sounds, thunder & lightning | Industrial units, vehicle noise, use of entertainment devices (loudspeakers, radios), etc. |
Impacts
- High blood pressure, migraine, stomach ulcer, irritability, insomnia, etc.
Measures to Control Noise Pollution
- Use of noise barrier materials
- Tree plantation (along transport routes)
- Regulation of loudspeakers, horns, etc.
- Use of sound absorbers
- Town planning arrangements
- Awareness and education, etc.
Permissible Noise Levels (Decibels)
| Area Type | Day Time (dB) | Night Time (dB) |
|---|---|---|
| Industrial area | 75 | 70 |
| Commercial area | 65 | 55 |
| Residential area | 55 | 45 |
| Silent zone | 50 | 40 |
⚠ EXAM TRAP
Silent zone has the LOWEST permissible noise limits (50 dB day / 40 dB night) — even lower than residential areas. Frequently swapped in MCQs.
☢ Radioactive Pollution
- Pollution caused by radiation from radioactive substances (Uranium, Thorium, Plutonium, etc.).
| Natural Sources | Man-made Sources |
|---|---|
| Solar, cosmic, terrestrial (rock, soil, etc.) | Nuclear testing, nuclear weapons, nuclear reactors, uranium mining, etc. |
Impacts
- Long-term consequences: genetic mutations, cancer, tumor and infertility.
- Affects structure of DNA, RNA and protein.
- Bone cancer → caused by Strontium-90.
- Red Blood Cell (RBC) damage → caused by Iodine-131.
🗑 Solid Waste Pollution
SourcesUrban/Rural/Domestic/Industrial Waste, Nuclear Plant Waste, Organic Waste
Disposal MethodsLandfill, composting, vermiculture, pyrolysis, etc.
- E-Waste (Electronic Waste) → waste from TV, fridge, computer, mobile, etc.
- Incinerators → modern process of burning garbage.
📋 Master Quick-Revision Table
| Topic | Key Fact |
|---|---|
| Primary Pollutants | DDT, plastic, CO, CO₂, NO₂, SO₂, particulate matter → Acid rain |
| Secondary Pollutants | O₃, NH₃, HNO₃, H₂SO₄, SO₃, etc. |
| Air Pollution Act | 1981 |
| Jaundice | Virus (water-borne) |
| Minamata Disease | Mercury poisoning |
| Blue-baby Syndrome | Nitrates in water |
| Itai-Itai Disease | Cadmium |
| Black Foot Disease | Arsenic |
| BOD | Biochemical Oxygen Demand | O₂ for decomposition by microorganisms |
| Namami Gange Programme | Ganga river conservation effort |
| Noise Pollution | Sound intensity above 65 dB |
| Industrial area noise limit | Day: 75 dB | Night: 70 dB |
| Residential area noise limit | Day: 55 dB | Night: 45 dB |
| Silent zone noise limit | Day: 50 dB | Night: 40 dB |
| Radioactive Pollution cause | Radiation from Uranium, Thorium, Plutonium, etc. |
| Bone cancer — element | Strontium-90 |
| RBC damage — element | Iodine-131 |
| E-Waste | Waste from TV, fridge, computer, mobile, etc. |
| Incinerators | Modern process of burning garbage |
| Solid Waste disposal | Landfill, composting, vermiculture, pyrolysis |